The study investigates the impact of Phase Change Material (PCM) and nano Phase Change Materials (NPCM) on solar still performance. PCM and a blend of NPCM are placed within 12 copper tubes submerged in 1 mm of water to enhance productivity. Thermal performance is assessed across four major scenarios with a fixed water level of 1 mm in the basin. These scenarios include the conventional still, equipped with 12 empty copper rods and 142 g of PCM in each tube, as well as stills with NPCM Samples 1 and 2. Sample 1 contains 0.75% nanoparticle concentration plus 142 g of PCM in the first 6 tubes, while Sample 2 features 2% nanoparticle concentration plus 142 g of PCM in the subsequent 6 tubes. Aluminum oxide (Al2O3) nanoparticles ranging in size from 20 to 30 nm are utilized, with paraffin wax (PW) serving as the latent heat storage (LHS) medium due to its 62 °C melting temperature. The experiments are conducted under the local weather conditions of Vaddeswaram, Vijayawada, India (Latitude-80.6480 °E, Longitude-16.5062 °N). A differential scanning calorimeter (DSC) is utilized to examine the thermal properties, including the melting point and latent heat fusion, of the NPCM compositions. Results demonstrate that the addition of nanoparticles enhances both the specific heat capacity and latent heat of fusion (LHF) in PCM through several mechanisms, including facilitating nucleation, improving energy absorption during phase change, and modifying crystallization behavior within the phase change material. Productivity and efficiency measurements reveal significant improvements: case 1 achieves 2.66 units of daily production and 46.23% efficiency, while cases 2, 3, and 4 yield 3.17, 3.58, and 4.27 units of daily production, respectively. Notably, the utilization of NPCM results in a 60.37% increase overall productivity and a 68.29% improvement in overall efficiency.

The Purpose of this work is to develop a niobium based metal matrix alloy through sintering based powder metallurgy technique. The 2, 4 and 6 weight percentage of Titanium Carbide (TiC) is added to the alloy. Various material properties such as hardness, tensile strength, impact strength and density are measured after the addition of TiC particle. The characterization, microstructure and particle size of the developed metal matrix are learnt through Scanning Electron Microscope (SEM) and Energy Dispersive Analysis of x-rays (EDAX). Finally, the synthesized niobium metal matrix is machined by unconventional machining processes namely Ultrasonic Machining (USM) and Laser Beam Machining (LBM) processes. The various input and output parameters have been considered for this experimental work. The most influential parameters on Material Removal Rate (MRR) and Surface Roughness (SR) are found by Analysis of variance. The systematic evaluation of optimal parameters of MRR and SR are carried out by using taguchi approach.

In recent years, lithium-ion batteries (LIBs) have gained attention and popularity due to their extended cycle life and high energy density. A hexagon-shaped 18,650 lithium-ion cylindrical cell battery pack was designed, incorporating paraffin wax (PA) as a phase change material (PCM) and nano-enhanced phase change material (Ne-PCM). However, the low thermal conductivity of the PCM causes a significant challenge to the development of electric vehicles (EVs). The highest temperature in the cylindrical cell battery pack is reached in the midregion, leading to an uneven temperature distribution across the cells. To overcome these challenges and achieve efficient battery module performance, phase change with nanomaterials such as graphene platelet nanopowder (GPN), multiwalled carbon nanotubes (MWCNTs), and graphite-synthetic powder (GSP) was placed in the center of four cells. Studies on the battery module were conducted without cooling, with PCM cooling, and with Ne-PCM cooling. The investigation revealed that the battery pack with Ne-PCM performed well, maintaining the temperature below 50 °C at different discharge rates of 1C, 2C, and 3C, and ensuring a uniform temperature variation within the cells. Ne-PCM decreased the temperature differential between the modules at 1C, 2C, and 3C discharge rates by 85.49%, 91.47%, and 84.21%, respectively, compared to PCM.

Currently world is encountering crisis such as diminution of fossil fuel resources and global warming due to engine emissions. Changing the operating parameters of the engine is one of feasible technique to enhance the engine performance. The present experimental work is mainly focuses on the influence of changing compression ratio along with different EGR rates for the research diesel engine fueled with 20% mango seed methyl ester (MSME 20).Transesterification process was used to reduce the viscosity of mango seed methyl ester. As per ASTM standards, the fuel properties of MSME and MSME20 were evaluated and compared with diesel. Initially, the compression ratio was varied at three levels such as 18:1, 20:1, and 22:1 for the diesel engine powered with 20% mango seed biodiesel blend and compared with diesel. Based on experimentation, it was found that MSME20 blend with compression ratio of 22:1 was shown enhanced brake thermal efficiency by 7.4% and also reduction in engine emissions such as carbon monoxide, hydrocarbon and smoke opacity by 33.3%, 40%, and 7.1% were found at full load respectively when compared to MSME20 with compression ratio of 18:1. However, there was considerable increment in NO_X emissions. In order to mitigate the NO_X emissions, the engine is further operated with different EGR rates (5% and 10%) at compression ratio of 22:1. The test results evident that addition of 5% of EGR to the engine running at compression ratio 22:1 reduced the NO_X emission levels by 40.5% over standard conditions without much penalty in engine performance.